A member with superior heat dissipation is favorably used as a submount of a semiconductor laser device (Japanese Patent Application Laid-open No. 2008-135629). Known examples of a member with superior heat dissipation include a single crystal SiC.
However, a plurality of pieces for submounts that are cut out from a single crystal SiC wafer include those having a hollow pipe-like defect referred to as a micropipe. When a micropipe is penetrated by a conductive member such as solder material, the insulating property of the single crystal SiC is destroyed and a semiconductor laser device using such a single crystal SiC becomes a defective product.